Re: Boltface Question
5" @ 100 yards?
No offense, but the only place you have to go is up!
Unless the machine work on the bolt face is done horribly bad, no it won't affect accuracy.
I say that knowing its a half truth. If you were for instance going from a 6mm PPC to a 600 nitro then yes, accuracy is definitely going to change, but it has nothing to do with the bolt face diameter, it'd be due to caliber selection.
There's an infinite number of ways to bed a rifle and with that comes an equally large number of ways to screw it up. I've written about this before, but for easy reference I'll say it again. If your interested in what my views are on it, just search and you'll see what I mean.
Bedding really doesn't do all that much for accuracy. It's not quite that simple. A well done bedding job is going to make a rifle perform reliably and predictably in a broader variety of conditions. Simply meaning cold/hot/dry/wet weather won't affect your group center as much.
Group center is the term to pay attention to. This is point of impact in relation to point of aim. This is where bedding really comes into play.
Group size is different all together and it does affect it as well, but its NOT the main reason for it. A rifle that shoots well (we'll use 1/2 moa as a baseline) will benefit from a good bedding job. It'll tighten things up a bit. What I mean is if the group is good, but suffers from a little vertical or maybe has a flier, bedding will tend to tame that down some. Again, a half truth as you also need to ensure the ammunition is working. Poor quality ammo (whether commercial or "home grown") is also going to cause these same characteristics.
Basically it's like this:
Accuracy starts with a great barrel. If there is one single thing to spend money on its the tube the bullet travels down. All the other tricks and wigits (properly done) will only improve from there.
My background involves professional drag racing. Look at a Pro Stock car from the NHRA. Everyone has a specific set of rules to run by in terms of engine specifications. By and large the power development from one car to another is not all that different. Within 20hp typically. So, the majority of them have it done "right". That last final 20hp is the "bedding", "trigger job", "blue printed" action, etc. In a competitive arena bound by common rules the little things add up quickly and when in capable hands yields a winning car.
Rifles are no different.
What I hope you take from this is that you first must ensure the meat and potatoes of your rifle are "right" (great barrel) before you start fiddling with the other things.